Introduction

Legg-Calve-Perthes disease (LCPD), a juvenile osteonecrosis of the femoral head (ONFH), can remain sequelae around hip joint, and results in osteoarthritis necessitating total hip arthroplasty (THA) in middle-age. THA for sequelae of LCPD needs specific concerns for anatomical deformity, leg length discrepancy (LLD), and relatively young patient's age. To date, few studies are available for the results of THA for LCPD sequelae. Moreover, there was no study for the result of Alumina-Alumina THA (Al-Al THA) in patient with LCPD sequelae, even excellent long term outcome of Al-Al THA has been documented in relatively young patients. The aim of this retrospective study is to evaluate the clinical and radiological outcome of Al-Al THA for LCPD sequelae, especially in terms of the restoration of LLD and the occurrence of complication. In addition, we compared the results of THA for LCPD sequelae with those for adult onset ONFH, in which THA is necessitated in relatively young age and excellent long term outcome has been proven after Al-Al THA.

Buechel and Pappas invented a modified version of LCS RP system (Co-Cr) with light material (Titanium), axial rotation limiting bar and improved conformity. The purpose of this prospective randomized study was to compare the minimum 3-year clinical outcomes including lightness, preference, and instability between the Co-Cr implant system and the Titanium implant system in bilateral total knee arthroplasty.

We prospectively enrolled 108 patients and 20 patients were lost to follow-up. Therefore, 88 patients (176 knees; mean age, 69.9±6.0years) were included in the study. The range of motion and clinical scores such as Knee Society score (KSS), Hospital for Special Surgery score (HSS) and Western Ontario and McMaster University (WOMAC) scores were measured preoperatively and postoperatively. At each follow-up, patients also complete a Likert scale questionnaire regarding subjective pain, lightness, left-right side preference (naturalness and satisfaction) and subjective instability.

There were no significant differences in all preoperative variables between two groups (p>.05). Mean follow-up period was 46.3±8.8 (36 to 72) months. The mean weight of Titanium implants was three times lighter than that of Co-Cr implants (133.9g versus 390.1g, p<.01). At the minimum of 3-year follow-up, there were no significant differences in pain, range of motion (ROM), clinical scores including KSS, HSS, and WOMAC between both groups. Also, the study showed no significant differences with subjective pain, lightness, preference (convenience, naturalness, and satisfaction), and subjective instability between the Co-Cr protheses and the Titanium protheses (p>.05).

No differences in clinical outcomes as well as subjective side-to-side differences between the Co-Cr prostheses and the Titanium prostheses were observed in the minimum 3-year follow-up. This implies that patients do not feel differently with two different weighted implants in mid-term follow-up.

Background

This study was conducted to assess the clinical and radiologic results of total knee arthroplasty (TKA) with an allogenic bone graft using varus-valgus constrained (VVC) prostheses in knees with severe bone defects and unstable neuropathy.

Introduction

Most surgeons that have performed kinematically aligned TKA have noticed an overall better clinical outcome, better motion, better patient satisfaction, and a quicker recovery than their patients treated with mechanically aligned TKA.

Introduction

Positive expectations can increase compliance with treatment and realistic expectations may reduce postoperative dissatisfaction. Recently there are articles regarding expectations of patients from their TKA in western literature and only few articles based on Korean populations which don't encompass the whole spectrum of expectations in Korean patients. In all those articles based on pre-operative expectation, results were applied to whole expectation category uniformly not differentially. We aimed to document the pre-operative expectations in Korean patients undergoing total knee replacement using an established survey form and to determine whether expectations were influenced by socio-demographic factors and socio-demographic factors influences expectation items in particular category uniformly or differentially.

Introduction

Unicompartmental knee arthroplasty (UKA) is becoming an increasingly popular option in single compartment osteoarthritis. As a result, diverse re-operations including revisions to total knee arthroplasty (TKA) has also increase. The objective of this study is to investigate the distribution of causes of re-operations after UKA and to analyze the types of re-operations.

Purpose

The purpose of this study was to demonstrate postoperative improvement and high satisfaction rates after a surgical approach that includes arthroscopic labral repair only, in patients with borderline dysplasia, without instability.

Objectives

To evaluate the clinical and radiographic outcomes of total knee arthroplasty using Vega® Knee System (B Braun-Aesculap, Tuttlingen, Germany) [Fig. 1] designed to allow high flexion by shortening the length of posterior condylar flange of femoral component after at least 2 year and to assess the occurrence of periprosthetic osteolysis and loosening at final follow-up.

Background

In this study, we investigated the long-term clinical results and survivorship of minimally invasive unicompartmental knee arthroplasty (UKA) by collecting cases that have been implanted for >10 years ago.

Purpose

To identify the modes of failure after total knee arthroplasty (TKA) in patients ≤ 55 years of age and to compare with those ≥ 56 years of age in patients who underwent revision TKA.

Among many factors that influence the outcomes of Total Knee Arthroplasties (TKAs), the mechanical alignment has played major roles for the success of TKA, the survival rates of the implants, and patient functionality. Most, but not all, studies have shown that alignment of the mechanical axis in the coronal plane within a range of 3° varus/valgus is associated with improved long-term function and increased survival rates. Robot-assisted TKA has been developed to improve improves the accuracy and precision of component implantation and mechanical axis (MA) alignment. We hypothesised that robot-assisted TKA would lead to a more accurate leg alignment and component implantation, and thus, improve radiological and clinical outcomes.

Between January 2003 and December 2004, a total of 98 primary TKA procedures were compared: 49 using a robotic-assisted procedure and 49 using conventional manual techniques. The cohorts were followed for 121.2 and 119.5 months on average, respectively. Radiographic assessments of the patients were performed preoperatively and at final follow-up and made according to the Knee Society Roentgenographic Evaluation System (KSRES) which included measurements of the coronal mechanical axis and sagittal and coronal inclinations of femoral and tibial components. The radiographic measurements were made using a PACS (Picture Archiving and Communication System). Clinical assessments were performed preoperatively, and at a final follow-up date that was a minimum of postoperative nine years. The clinical results included ranges of motion (ROM), Hospital for Special Surgery (HSS) scores, Western Ontario and McMaster University (WOMAC) scores (for pain and function).

The radiographic results showed no statistical differences when comparing the means of the two groups. When considering outliers (defined as error ≥ ±3°) for the mechanical axis, femoral coronal and sagittal inclinations, and tibial coronal and sagittal inclinations, the ROBODOC group had zero outliers for all measurements except for one in tibial sagittal inclination. On the other hand, the conventional group had 12 outliers for mechanical axis, 2 for femoral coronal inclination, 3 for femoral sagittal inclination, 3 for tibial coronal inclination, and 4 for tibial sagittal inclination. However, there were no statistically significant differences between groups for ROM, HSS, or WOMAC scores at the final follow-up.

The results of this study support previous work and demonstrate that the ROBODOC-assisted implantation of TKA results in better radiographic outcomes and better ligament balance with equivalent safety when compared to conventional TKA at a minimum follow-up of nine years.

Purpose

Although the use of stems in revision total knee arthroplasty (RTKA) enhances survival by improving the stability of implant, questions as to the optimal fixation method as well as the vertical extent of the cement, remain unanswered. This study aimed 1) to determine the correlation between the vertical extent of cement and implant loosening; and 2) to determine the minimum cementing extent for a stable implant in revision TKA with a hybrid technique.

Over the past twenty years, the Low Contact Stress Rotating Platform (LCS RP) showed good results. Buechel and Pappas invented the Buechel-Pappas Knee (B-P Knee) system that is a modified version of the LCS system with different material (titanium), axial rotation limiting bar and improved conformity. The purpose of this prospective randomized study was to compare the 2-year clinical outcomes between two implants in the same patients who had been operated with bilateral TKAs. We prospectively enrolled 107 patients and 18 patients were lost to follow-up. Therefore, 89 patients (178 knees; mean age, 69.8±6.0years) were included in the study. The range of motion and clinical scores such as Knee Society score (KSS), Hospital for Special Surgery score (HSS) and Western Ontario and McMaster University (WOMAC) scores were measured preoperatively and postoperatively. At each follow-up, patients also complete a Likert scale questionnaire regarding subjective pain, lightness, left-right side preference (naturalness and satisfaction) and subjective instability. There were no significant differences in all preoperative variables between the two groups(P<.05). Mean follow-up period was 29.9±7.2 months. At the 2-year follow-up, mean value of flexion contracture, further flexion and range of motion were not significantly different between both groups. Also, there were no significant differences in the clinical scores and in side to side difference for the feeling of laterality between two groups(P<.05). After minimum 2-year follow-up, we found no differences in early clinical outcomes as well as subjective side to side difference between the LCS RP and B-P Knee system in this study.

This study aimed to determine the optimal formulation of antibiotic-loaded bone cement (ALBC) for periprosthetic joint infection (PJI) using both in vitro and in vivo models incorporating various combinations of gram-positive and gram-negative antibiotics.

The in vitro antibiotic release characteristics and antibacterial capacities of ALBCs loaded with either 4 g of vancomycin or teicoplanin and 4 g of ceftazidime, imipenem, or aztreonam were measured against methicillin-susceptible S. aureus, methicillin-resistant S. aureus, coagulase-negative staphylococci, Pseudomonas aeruginosa and Escherichia coli. ALBC spacers with superior in vitro antibacterial capacity were then implanted into ten patients (five females and five males between 29 and 75 years of age) diagnosed with chronic hip/knee PJIs and antibacterial activities within joint fluid were measured. The average duration of ALBC spacer implantation was 80 days (range, 36–155 days). Antibiotic concentrations and antibacterial activities of joint fluid at the site of infection were measured during the initial period as well as several months following spacer implantation.

Cement samples loaded with vancomycin/ceftazidime or teicoplanin/ceftazidime exhibited equal or longer antibacterial duration against test bacteria as compared with other ALBCs. Joint fluid samples exhibited antibacterial activity against the test microorganisms including ATCC strains and clinically isolated strains. There were no adverse systemic effects, infection at second stage re-implantation, or recurrent infection at final follow-up.

Vancomycin/ceftazidime ALBC provided broad antibacterial capacity both in vitro and in vivo and was shown to be an effective and safe therapeutic measure in the treatment of hip/knee PJIs.

We thank H.Y. Hsu for performing bioassay.

The objective of this study was to compare the elution characteristics, antimicrobial activity and mechanical properties of antibiotic-loaded bone cement (ALBC) loaded with powdered antibiotic, powdered antibiotic with inert filler (xylitol), or liquid antibiotic, particularly focusing on vancomycin and amphotericin B.

Cement specimens loaded with 2 g of vancomycin or amphotericin B powder (powder group), 2 g of antibiotic powder and 2 g of xylitol (xylitol group) or 12 ml of antibiotic solution containing 2 g of antibiotic (liquid group) were tested.

Vancomycin elution was enhanced by 234% in the liquid group and by 12% in the xylitol group compared with the powder group. Amphotericin B elution was enhanced by 265% in the liquid group and by 65% in the xylitol group compared with the powder group. Based on the disk-diffusion assay, the eluate samples of vancomycin-loaded ALBC of the liquid group exhibited a significantly larger inhibitory zone than samples of the powder or the xylitol group. Regarding the ALBCs loaded with amphotericin B, only the eluate samples of the liquid group exhibited a clear inhibitory zone, which was not observed in either the xylitol or the powder groups. The ultimate compressive strength was significantly reduced in specimens containing liquid antibiotics.

Adding vancomycin or amphotericin B antibiotic powder in distilled water before mixing with bone cement can significantly improve the efficiency of antibiotic release than can loading ALBC with the same dose of antibiotic powder. This simple and effective method for preparation of ALBCs can significantly improve the efficiency of antibiotic release in ALBCs.

We thank H.Y. Hsu for performing the bioassay.

The aim was to compare the efficacy of selective ultrasound-screening (SUSS) for developmental dysplasia of the hip (DDH) to clinical screening alone, by comparing outcomes in a contemporary group with those from a 40 year old cohort.

This was a retrospective cohort study. The department's DDH and surgical databases were used to identify all cases of DDH, and all cases of surgery for DDH during the study period (2009–13). Patients born outside our region, and teratologic cases were excluded from analysis. The Obstetric database provided the total number of live births over the five-year period. This data was used to calculate the incidence of late-diagnosis (age over 3 months) DDH and the rate of surgery for DDH in our region. These results were compared to those of a similar study from our institution published in 1977, after the introduction of universal clinical screening. Relative risk (RR) was calculated for the two groups, and analysed for statistical significance.

The incidence of late-diagnosis DDH over the recent 5-year study period was 0.66/1000 live births, compared to 0.6/1000 in the control group. The RR for late-diagnosis DDH was not significantly different between the two groups (RR 1.14, 95% CI 0.6 to 2.2). The rate of surgery for DDH was 0.86/1000, compared to 0.9/1000 live births in the control group. The RR for surgery for DDH in the current study population compared to the historic control was 0.97, but this difference was not statistically significant (95% C.I. 0.57 to 1.68; p=0.92).

Despite advances in screening for DDH over the last 40 years, neither the incidence of late diagnosis DDH, nor rates of surgery for DDH in our region have changed. Whilst previous studies have demonstrated that SUSS does not eliminate late-presenting DDH, this study suggests it confers no advantage over clinical screening alone.

Summary Statement

Low-intensity pulsed ultrasound (LIPUS) enhanced osteogenic differentiation of osteoprogenitor cells derived from mouse induced pluripotent cells (iPSCs) without embryoid body formation. Our findings provide insights on the development of LIPUS as an effective technology for bone regeneration strategies using iPSCs.

The purpose of this study was to compare the results of proximal and distal chevron osteotomy in patients with moderate hallux valgus.

We retrospectively reviewed 34 proximal chevron osteotomies without lateral release (PCO group) and 33 distal chevron osteotomies (DCO group) performed sequentially by a single surgeon. There were no differences between the groups with regard to age, length of follow-up, demographic or radiological parameters. The clinical results were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) scoring system and the radiological results were compared between the groups.

At a mean follow-up of 14.6 months (14 to 32) there were no significant differences in the mean AOFAS scores between the DCO and PCO groups (93.9 (82 to 100) and 91.8 (77 to 100), respectively; p = 0.176). The mean hallux valgus angle, intermetatarsal angle and sesamoid position were the same in both groups. The metatarsal declination angle decreased significantly in the PCO group (p = 0.005) and the mean shortening of the first metatarsal was significantly greater in the DCO group (p < 0.001).

We conclude that the clinical and radiological outcome after a DCO is comparable with that after a PCO; longer follow-up would be needed to assess the risk of avascular necrosis.

Cite this article: Bone Joint J 2013;95-B:649–56.

Introduction

Low-intensity pulsed ultrasound (LIPUS) has been reported to enhance healing of fracture and nonunion. Bone morphogenetic protein-7 (BMP-7) has also been reported to promote bone formation. Recently, we demonstrated progenitor cells with osteogenic/chondrogenic differentiation potential existed in human fracture hematoma and nonunion tissue.

Introduction

Our previous study using microarray analysis showed that Rad (Ras associated with diabetes) was highly expressed in nonunion. The purpose of this study is to investigate the gene expression and immunolocalization of Rad, and other Ras-related G proteins: Rem1 and Rem2 in fracture/nonunion site using rat experimental models.